Wireless connection - Link speed

I got my new Vizio Co-star and set it up to use the wireless connection. But the link speed is 64Mbps. The wireless router I've supports upto 300Mbps and other client do get link speed of 270Mbps. I wonder why would Co-star show only 64Mbps. Any idea?

Are you using the Co-Star's speed test? There was a thread a while ago that showed that the internal speed test was far from accurate usually showing lower speeds. If not which speed test are you using?